Rotary toothbrush



Dec. 4, 1928. 1,693,964

' E. F. SMITH ROTARY TOOTHBRUSH Filed June 1, 1927 IN VEN TOR.

Y Edvard 311/17? Patented Dec. 4, 1928.

UNITED STATES EDWARD 1'. SMITH, OF LOS ANGELES, CALIFORNIA.

ROTA RY TQOTHBRUSH.

Application filed June 1,

My invention relates to a device for cleaning the teeth by brushing and it has particular reference to a simple and economical ower driven brush which may be conveniently inserted into the mouth and by whlch a thorough cleaning of the dentition and removal of accumulations between the teeth may be effected.

The objects of the invention are to pro vide an inexpensive tooth brushing dev1ce in combination with a driving or rotating mechanism therefor, to provide a simple device of this character in which the brush employed may be conveniently replaced, and to provide a convenient support for the brush by which the flesh in the mouth Wlll be protected against the brush dur1ng the operation thereof. These and other OlJJGZTtS are accomplished by the device which I have illustrated in preferred form in the accompanying drawing, in which ig. 1 isa plan view of the 'dGVlCG embodying my invention;-

Fig. 2 is a sectional elevation, and

Fig. 3 is a detailof a polishing un1t.'

My invention consists in a bfoad sense of a power driven flexible shaft to which 1s connected a rigid shaft carrying a chuck, a housing for the rigid portion of the shaft, which forms ahandle, and a brush mounted on a rod or shaft,'the shaft having one end secured in and by said chuck,tand the other end mounted in a bearing carried by said housing.

, In a more s ecific sense, the invention comprises a flexib e shaft 1, which includes in its assembly such shaft, a rigid shaft 2', connected with said flexible shaft, and a casing 3 Within and relative to which said shafts 1 and 2 are rotatable. Arranged fordetachable association with said casing 3 is a housing 4, forming a handle for the user of' the device. This housing 4, as seen, is preferably made in two parts 4 and 4 the part 4 being provided with an internal bored hearing 5, which projects beyond the end of said part 4, and the part 4' being fitted over the projecting end of said bearing 5 and arranged to be locked therein and in sn'ug engagement with the end of said part 4 by any suitable means, as by bayonet connection. Through the bore 5 of said bearing 5 is extended a stem 6, which at one end is arranged forinterfitting detachable connection with the end of said rigid shaft 2.

1927. Serial No. 19am.

For the purpose of co-operating for rotation with said shaft 2, the latter is provided with a key 7 that is arranged to fit in a longitudinal slot 6' in said stem. The connection of the rigid shaft 2 and the stem 6 is insured and the longitudinal displacement of said stein 6, when the part 4 is disconnected from the part 4, is prevented, by a set screw 6" projecting through the part 4 of the, housing 4, through the bearing '5, and intoa circumferential groove 5" provided in said bearing 5. The other end of said stem 6 is provided with longitudinal externally threaded spaced fingers 8 which, by means of a nut 9 engaging the threads on said extensions 8, are arranged -to be pressed toward one another and to grip an article interposed therebetween. The fingers 8 in conjunction with the nut 9 constitute substantially a chuck, and this term is used herein to indicate the gripping end of the stem 6. The part 4' of the housing handle 4 is formed or provided with an out- I wardly directed guard portion 10, of curviform cross section, and the end of said guard portion 10 is bent at substantially right angles thereto to provide a bearing for one vend of the shaft 11 of a brush 11. The other end of said shaft 11' is arranged to be secured in said chuck, and access to nut 9 of thechuck assembly for tightening the fingers 8 upon said shaft 11' is afforded by oppositely disposed openings 12 in. said part 4. In order to hold stationary the shaft 2, and the parts connected therewith, during the adjustment of the nut 9 for operating the fingers 8 into engagement or disengagement with the brush shaft 11, I provide a stop 13 which is mounted on the end of a spring member 14 secured on the outside of the part 4 of the housing 4. This stop 13 extends through an opening in the wall of said part 4, pressed into the slot 6 in said stem 6,

whereby therotation of said stem 6, and

the parts associated therewith will be prevented, itbeing understood that the adjustment of said nut 9 must occur while the motor is at rest.

The guard portion 10, referred to, is, as stated, provided to support the free end of the shaft 11' of the brush 11, which is of longitudinal extent equal substantially to the length of'an ordinary tooth brush; but, in addition to that function, it serves to and is arranged to be protect the flesh of the mouth from bristles durin the operation of cleaning the teeth. For t is purpose the guard is curviform and exposes only so much of the bristle area as is needed. As shown in the drawing, this guard ortion 10 is preferably an integral part 0 the tubular housing part 4 and s preferabl bent beyond the exterior longitudinal p ane of the part 4" for the urpose of accommodating a brush lar r t an the diameter of said part 4'' won d otherwise ermit. The brush 11 described herein, may replaced b a buffer, such as shown at 15, Fig. 3, or y any other device.

What I claim, is:

1. In a device of the character described,-

a housing forming a handle and provided at one end thereof with a guard, a shaft within said housing and rotatable relatively thereto, a hearing within said housing,

a stem extending through said bearing and removably conjoined at one end with' said shaft and at the other end provided with a chuck means engaging said stem to prevent disengagement thereof with said shaft, a brush 'ournaled at one end in said guard and having its other end secured in said chuck, said housing havin ope'nings through which access may be tosaid chuck for manipulating same and means to operate said shaft. 7

2. A rotary tooth brush comprising a housing forming a handle and provided at one end thereofwith a guard, a shaft within said housing and rotatable relatively thereto.

a gripping means provided on the end of said shaft, a brush journaled at one end in said guard and at the other end arranged for engagement by said'gripping'mcans, and means to hold the shaft against rotation during the operation of said gripping means.

3. In a device of the character described, a-housing provided at one end thereof with a guard, a shaft within said housing and rotatable relatively thereto, said shaft provided with a key, a stem associated with said shaft for rotation therewith, said stem having a longitudinal slot through which the key of said shaft extends whereby the-shaft during the rotation thereofm'ay move longitudinally relative to said stem, a gripping means on said stem, a brush journaled at one end in said guard and having its other end secured in said gripping means, and means to operate said shaft.

In testimony whereof I have set my hand.

EDWARD F. SMITH. 

